Optical transmission systems are becoming increasingly prevalent in modern telecommunication networks. They offer the advantages of a low cost wideband transmission medium requiring amplification at relatively long spacing and support a very large number of simultaneous communications over each of the optical fibers that constitute the transmission medium. Voice, data, and video are communicated as digital signals over the optic fibers to minimize noise and distortion of the signals over long distance transmission.
A problem in the prior art exists in that while optical transmission systems can carry large numbers of separate communications, no satisfactory method exists for inserting and removing selected communications at a node in a transmission network, or switching selected communications from one optical fiber to another, without converting the signals into electrical signals, processing the electrical signals at a slower rate, and reconverting them into high speed optical signals.